Remote presentation protocols such as the ICA protocol manufactured by Citrix Systems, Inc., of Ft. Lauderdale, Fla., the X protocol by the X.org Foundation, the Virtual Network Computing protocol of AT&T Corp., or the RDP protocol, manufactured by Microsoft Corporation of Redmond, Wash., are inherently stateful. In order to view a particular point in a stream of recorded presentation protocol data, playback of the stream must begin from the very beginning of stream and played back sequentially until the particular point is encountered.
Conventional techniques for accessing a recorded stream of data out of sequential order typically involve the use of keyframes and delta frames. Keyframes are typically stored within the stream itself as synchronization points so that frames may be quickly reproduced on a screen. Delta frames typically describe differences from previous frames to produce the visible video frame.
Since remote presentation protocols are typically compact due to their stateful nature, the additional storage of keyframes increases file size by several orders of magnitude. Even with modern digital video compression techniques, keyframes generally add several orders of magnitude to the storage required for a stream of recorded presentation protocol data. However, omitting keyframes results in a non-seekable protocol. A method for seekability without the overhead of oversized files caused by stored keyframes is desirable.